A073987 Number of strings of length n over Z_6 with trace 2 and subtrace 4.

0, 1, 3, 12, 126, 1296, 9072, 52488, 297432, 1700352, 9843120, 58576608, 356638464, 2176782336, 13162730688, 78940272384, 471877757568, 2821109907456, 16894457846784, 101361597378048, 608764662139392, 3656220357427200, 21947909832446976, 131685972252346368

Offset

1,3

Comments

Same as the number of strings of length n over Z_6 with trace 4 and subtrace 4.

Links

Table of n, a(n) for n=1..24.

Max Alekseyev, PARI/GP scripts for miscellaneous math problems

F. Ruskey Strings over Z_6 with given trace and subtrace

Formula

a(n; t, s) = a(n-1; t, s) + a(n-1; t+5, s+5t+1) + a(n-1; t+4, s+4t+4) + a(n-1; t+3, s+3t+3) + a(n-1; t+2, s+2t+2) + a(n-1; t+1, s+t+1) where t is the trace and s is the subtrace.

Crossrefs

Cf. A073971, A073972, A073973, A073974, A073975, A073976, A073977, A073978, A073979, A073980, A073981, A073982, A073983, A073984, A073985, A073986, A073988, A073989, A073990, A073991, A073992, A073993, A073994.

Sequence in context: A209065 A124153 A162127 * A317802 A138392 A152544

Adjacent sequences: A073984 A073985 A073986 * A073988 A073989 A073990

Keyword

easy,nonn

Author

Frank Ruskey and Nate Kube, Aug 16 2002

Extensions

Terms a(11) onward from Max Alekseyev, Apr 09 2013

Status

approved